Express a 100 kg mass in units of slugs, blobs, and lbm. How much does this mass weigh in lbf and in N?
The Correct Answer and Explanation is :
To express a mass of 100 kg in units of slugs, blobs, and lbm, as well as to determine the weight in lbf and N, we will follow these steps:
Step 1: Conversion of mass (100 kg) to slugs, blobs, and lbm
- Slugs: The slug is the unit of mass in the Imperial system. The conversion factor from kilograms to slugs is:
[
1 \text{ kg} = 0.0685218 \text{ slugs}
]
Therefore, to convert 100 kg to slugs:
[
100 \text{ kg} \times 0.0685218 \text{ slugs/kg} = 6.85218 \text{ slugs}
] - Blobs: The blob is a less commonly used unit, mainly in certain physics contexts, defined as:
[
1 \text{ blob} = 1 \text{ kg}
]
So, 100 kg is equivalent to 100 blobs. - Lbm (Pound Mass): The pound mass (lbm) is a unit of mass in the Imperial system, where:
[
1 \text{ kg} = 2.20462 \text{ lbm}
]
Therefore, to convert 100 kg to lbm:
[
100 \text{ kg} \times 2.20462 \text{ lbm/kg} = 220.462 \text{ lbm}
]
Step 2: Determining weight in lbf and N
Weight is the force exerted by gravity on an object, and is given by the formula:
[
W = m \times g
]
Where:
- ( m ) is mass
- ( g ) is the acceleration due to gravity.
In the Imperial system:
- To convert from lbm to lbf (pound-force), the standard acceleration due to gravity is approximately 32.174 ft/s²:
[
W_{\text{lbf}} = 100 \text{ lbm} \times \frac{32.174 \text{ ft/s}^2}{32.174 \text{ ft/s}^2} = 100 \text{ lbf}
]
So the weight in lbf is 100 lbf.
In the SI system:
- To convert mass to weight in newtons (N), we use:
[
W_{\text{N}} = 100 \text{ kg} \times 9.81 \text{ m/s}^2 = 981 \text{ N}
]
So the weight in N is 981 N.
Summary:
- 100 kg = 6.85218 slugs
- 100 kg = 100 blobs
- 100 kg = 220.462 lbm
- Weight = 100 lbf (in the Imperial system)
- Weight = 981 N (in the SI system)